Evaluation Of Spatiotemporal Variability Of Hydrometeorological Elements In Daqinghe River Basin

Taking Daqinghe River Basin as the main research area,the variation measurement of hydrological and meteorological elements in the plain area and mountainous area of Daqinghe River Basin was identified from three aspects of temporal variation,spatial variation and temporal variation,which laid a foundation for water resources planning,management and security guarantee in Xiong'an New Area.According to the collected data of rainfall,temperature,evaporation,runoff and groundwater depth data,first of all,from the aspects of time variation,selection of time variation index to build index system,and uses the change point diagnosis,correlation coefficient method,multiple time scale entropy methods for index quantification,analysis on the time evolution law of hydrologic meteorological elements and characteristics;Secondly,constructs the index system of space mutation:using statistical half the variation function of constructing large spatial distribution model of qinghe watershed hydrologic meteorological elements,and the spatial variation of intensity,degree of spatial autocorrelation,spatial direction and the main components of the spatial variation of variation space variation index calculation,analysis of the evolution of the hydrologic meteorological elements in space;Finally,using the combination of subjective and objective weighting method to calculate the index weight,analysis the importance of every index and the index weight calculation method combined with TOPSIS evaluation model of hydrological meteorological elements of time variation,spatial variation and time variation in classification and evaluation,on the basis of the evaluation results to determine the time variation of hydrologic meteorological elements measurement,spatial variation and temporal and spatial variation measure.The main research results are as follows:(1)In the temporal variation,there was no temporal variation in rainfall in Daqinghe River Basin,while the temperature,evaporation,groundwater in plain area and runoff in mountainous area showed jumping variation in 1993,1983,1998 and 1979,and showed increasing,decreasing,decreasing and sharply decreasing trends,respectively.In addition to the depth of groundwater,the temperature,evaporation and runoff all showed short,medium and long periodic changes;Through the calculation and classification of index evaluation system,it can be seen that the temperature in plain area has strong time variation,while the temperature in mountainous area is general time variation.Evaporation in plain area shows strong time variation,while in mountainous area it shows weak time variation.The groundwater depth in plain area showed weak time variation,while the runoff in mountainous area showed strong time variation.(2)In the spatial variation,except for rainfall,temperature and plain evaporation in mountainous areas,Gaussian model was selected as the spatial distribution model for other variables.Rainfall,temperature,evaporation,groundwater depth and runoff all had a moderate degree of spatial autocorrelation.According to the index evaluation system and classification calculation,the spatial variation degree of air temperature in plain area and mountainous area is strong.The spatial variation degree of evaporation in plain area is strong,while the spatial variation degree of evaporation in mountainous area is weak.The degree of spatial variation of groundwater depth in plain area is general.The spatial variation of runoff in mountainous areas is weak.(3)For the temporal and spatial variability,the degree of temporal and spatial variability of temperature in plain area is stronger than that in mountainous area,and the importance of temporal variation of temperature is slightly less than that of spatial variation.Evaporation in plain area and mountainous area shows strong and weak temporal and spatial variability respectively,and the importance of evaporation in temporal variation is slightly greater than that in spatial variation.The temporal and spatial variation degree of groundwater depth in plain area is general,and the importance of groundwater depth in temporal variation is far less than that in spatial variation.The degree of temporal and spatial variation of runoff in mountainous areas is general,and the importance of temporal variation of runoff is much greater than that of spatial variation.